1. Field of the Invention
The invention relates to a device and a method for displacing mown crop. In particular, the invention relates to so-called mobile rake devices, provided with at least two rake wheels which are equal in construction. Each rake wheel comprises a rotor driven around a rotor point of rotation, from which rotor a number of arms extend outwardly, which arms are provided, near their outer ends, with rake pins or tines. The rotor centre line of each rake wheel extends through the rotor point of rotation and is oriented substantially vertically in the operative position of the rake wheel.
2. Description of the Related Art
As a result of the device being moved, each rake wheel has a strip-shaped working area and displaces the crop lying on the mowing field in that working area sidewardly, to form a windrow. The two rake wheels, which are rotated in the same direction, are arranged obliquely behind each other in the direction of travel, so that the—strip-shaped—working area of the rear rake wheel can be adjacent to the working area of the front rake wheel, in order thus to achieve together a path-shaped working range. The rear rake wheel should displace the (pre) windrow produced by the front rake wheel and the crop lying scattered in its strip-shaped working area further sidewardly, to form a final windrow. An example of such a device is shown in EP 0.779.021, which is hereby incorporated by reference in its entirety.
In this case, the rear rake wheel has to achieve a higher performance than the front rake wheel. For this reason, the rear rake wheel is sometimes driven by another number of arms and/or at another speed than the front rake wheel. In this case, several rake wheel embodiments have to be produced and kept in stock. The drive of both rake wheels should also be configured for this purpose.